1. Field of the Invention
The present invention relates to a composite metal product made by compositing a carbon nano material with a low melting point metal material by injection molding and to a method of producing the same.
2. Description of the Related Art
A carbon nano material, which is a kind of crystalline carbon materials, has such characteristics that its heat conductivity is about five times or more as high as that of aluminum (Al), magnesium (Mg) and the like, it is excellent in electric conductivity, and it is also excellent in slidability because it has a low friction factor. Since the carbon nano material is very minute, however, it is said that the material is preferably used by being composited with other material.
In a conventional method, a composite material is obtained by mixing the carbon nano material and metal powder, pressing and pulverizing said mixture so that the particle size is from 5 μm to 1 nm, and a composite product is obtained by hot pressing the composite material. In the above method, the composite material is easily oxidizable because the metal is used in the form of fine powder, and, in particular, the compositing method for preparing the composite material has a problem in that it is difficult to apply the method to metals such as magnesium and the like because if they are used in the form of fine powder, they may be broken into a spontaneous flame by oxidization.
The composite material particles must be pressed and molded in an inert gas atmosphere at a low temperature of 0° C. or less and also must be placed in the inert gas atmosphere when it is molded by the hot press, and further there is a limitation in the product of the composite materials that can be manufactured by the hot press molding. Accordingly, a problem arises in that metal products of electronic equipments such as heat sinks, shields and bearings and the like, which are difficult to be molded by a press from the composite material containing the crystalline carbon material.